First off, you don't use a ring light for shooting people. A ring light provides even lighting and you don't want that. It is shadows that reveal depth and contour and a ring light will make your models look like cardboard cutouts.
Second: backdrops are easy. You will need a couple of light stands to support a bar; the bar holds up the backdrop. Black velvet is the backdrop of choice for a black background. White can be either cold pressed paper or white velvet. The velvet is non-reflective, so you don't get hot spots (reflections from the lights). If you want an Olan Mills type backdrop, get a piece of cotton duck canvas, some paint in the color desired and a small amount of black and white paint (flat finish oil-based enamel). Take a sponge and dab on the paint, darkening it toward the edges of the canvas and lighter toward the center (that is what the black and white paints are for -- darkening and lightening the paint by mixing with it).
Third: What you will want to get for lights is a three or four light setup, to start with. Later, you will probably want one or two more. You have some choices to make here: strobes or hot lights.
If you get strobes, Alien Bees are a popular brand and are probably the most affordable. White Lightning strobes are my favorites though. If you get strobes, you need to be aware that the meter in your camera will not work with them, so you will also need to budget for a hand held flash meter. Gossen and Sekonic make the best handheld meters.
If you get hot lights, there are several varieties. Tungsten will be the least problematic while florescent and halogen will be the most problematic. By the way, the term "hot lights: refers to the fact that the circuit in the lights is hot (they are always on), not to the temperature of the lights (although halogen lights DO produce a lot of heat). Tungsten lights look like blue lightbulbs; the blue corrects the color, and they are usually about 250-watts. Light is cumulative, so three of these will produce 750-watts -- more than enough for anybody.
Third: Pointing the lights directly at the model will produce very harsh light, so you need some modifiers. About the cheapest you can get that will work well will be umbrellas. You will need the umbrellas and some clamps (that attach them to the light stands). Umbrellas are commonly available in white, silver and gold. The rule of thumb is that you use white for natural skin tones and gold if you want your subject to look a little more tanned. Silver is not usually used for shooting people. You aim the lights AWAY from the model and reflect it back onto the model with the umbrella. This softens the light and give you shadows with softer edges, which are more flattering.